Techniques and apparatuses for variable timing adjustment granularity

ABSTRACT

Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may determine at least one of a granularity or range of a timing adjustment value based at least in part on at least one of a timing adjustment command indicating the granularity, configuration information indicating the granularity, information regarding a communication, carrier, or band associated with the user equipment, or a combination thereof; and/or perform timing adjustment based at least in part on at least one of the granularity or the range of the timing adjustment value. Numerous other aspects are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS UNDER 35 U.S.C. § 119

This application is a continuation of U.S. patent application Ser. No.16/058,765, filed Aug. 8, 2018 (now U.S. Pat. No. 11,032,816), entitled“TECHNIQUES AND APPARATUSES FOR VARIABLE TIMING ADJUSTMENT GRANULARITY,”which claims priority to U.S. Provisional Patent Application No.62/543,653, filed on Aug. 10, 2017, entitled “TECHNIQUES AND APPARATUSESFOR VARIABLE TIMING ADJUSTMENT GRANULARITY,” which are hereby expresslyincorporated by reference herein.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wirelesscommunication, and more particularly to techniques and apparatuses forvariable timing adjustment (TA) granularity.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, etc.). Examples of such multiple-access technologiesinclude code division multiple access (CDMA) systems, time divisionmultiple access (TDMA) systems, frequency-division multiple access(FDMA) systems, orthogonal frequency-division multiple access (OFDMA)systems, single-carrier frequency-division multiple access (SC-FDMA)systems, time division synchronous code division multiple access(TD-SCDMA) systems, and Long Term Evolution (LTE). LTE/LTE-Advanced is aset of enhancements to the Universal Mobile Telecommunications System(UMTS) mobile standard promulgated by the Third Generation PartnershipProject (3GPP).

A wireless communication network may include a number of base stations(BSs) that can support communication for a number of user equipment(UEs). A user equipment (UE) may communicate with a base station (BS)via the downlink and uplink. The downlink (or forward link) refers tothe communication link from the BS to the UE, and the uplink (or reverselink) refers to the communication link from the UE to the BS. As will bedescribed in more detail herein, a BS may be referred to as a Node B, agNB, an access point (AP), a radio head, a transmit receive point (TRP),a new radio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent user equipment to communicate on a municipal, national,regional, and even global level. New radio (NR), which may also bereferred to as 5G, is a set of enhancements to the LTE mobile standardpromulgated by the Third Generation Partnership Project (3GPP). NR isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrating with other open standards usingorthogonal frequency division multiplexing (OFDM) with a cyclic prefix(CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g.,also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) onthe uplink (UL), as well as supporting beamforming, multiple-inputmultiple-output (MIMO) antenna technology, and carrier aggregation.However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in LTE and NRtechnologies. Preferably, these improvements should be applicable toother multiple access technologies and the telecommunication standardsthat employ these technologies.

SUMMARY

In some aspects, a method for wireless communication performed by a userequipment may include determining at least one of a granularity or rangeof a timing adjustment value based at least in part on at least one of atiming adjustment command indicating the granularity, configurationinformation indicating the granularity, information regarding acommunication, carrier, or band associated with the user equipment, or acombination thereof, wherein the granularity or the range is variablebased at least in part on the communication, carrier, or band associatedwith the user equipment; and performing timing adjustment based at leastin part on at least one of the granularity or the range of the timingadjustment value.

In some aspects, a user equipment for wireless communication may includea memory; and one or more processors, the memory and the one or moreprocessors configured to: determine at least one of a granularity orrange of a timing adjustment value based at least in part on at leastone of a timing adjustment command indicating the granularity,configuration information indicating the granularity, informationregarding a communication, carrier, or band associated with the userequipment, or a combination thereof, wherein the granularity or therange is variable based at least in part on the communication, carrier,or band associated with the user equipment; and perform timingadjustment based at least in part on at least one of the granularity orthe range of the timing adjustment value.

In some aspects, a non-transitory computer-readable medium may store oneor more instructions for wireless communication. The one or moreinstructions, when executed by one or more processors of a userequipment, may cause the one or more processors to determine at leastone of a granularity or range of a timing adjustment value based atleast in part on at least one of a timing adjustment command indicatingthe granularity, configuration information indicating the granularity,information regarding a communication, carrier, or band associated withthe user equipment, or a combination thereof, wherein the granularity orthe range is variable based at least in part on the communication,carrier, or band associated with the user equipment; and perform timingadjustment based at least in part on at least one of the granularity orthe range of the timing adjustment value.

In some aspects, an apparatus for wireless communication may includemeans for determining at least one of a granularity or range of a timingadjustment value based at least in part on at least one of a timingadjustment command indicating the granularity, configuration informationindicating the granularity, information regarding a communication,carrier, or band associated with the apparatus, or a combinationthereof, wherein the granularity or the range is variable based at leastin part on the communication, carrier, or band associated with theapparatus; and means for performing timing adjustment based at least inpart on at least one of the granularity or the range of the timingadjustment value.

Aspects generally include a method, apparatus, system, computer programproduct, non-transitory computer-readable medium, user equipment,wireless communication device, and processing system as substantiallydescribed herein with reference to and as illustrated by theaccompanying drawings and specification.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description, and not as a definition of the limits ofthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalaspects of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective aspects. The same reference numbers in different drawings mayidentify the same or similar elements.

FIG. 1 is a block diagram conceptually illustrating an example of awireless communication network, in accordance with various aspects ofthe present disclosure.

FIG. 2 is a block diagram conceptually illustrating an example of a basestation in communication with a user equipment (UE) in a wirelesscommunication network, in accordance with various aspects of the presentdisclosure.

FIG. 3 is a block diagram conceptually illustrating an example of aframe structure in a wireless communication network, in accordance withvarious aspects of the present disclosure.

FIG. 4 is a block diagram conceptually illustrating two example subframeformats with the normal cyclic prefix, in accordance with variousaspects of the present disclosure.

FIG. 5 is a diagram illustrating an example of configuring a variabletiming adjustment granularity for New Radio, in accordance with variousaspects of the present disclosure.

FIG. 6 is a diagram illustrating an example of configuring a variabletiming adjustment granularity for New Radio, in accordance with variousaspects of the present disclosure.

FIG. 7 is a diagram illustrating an example of configuring a variabletiming adjustment granularity for New Radio, in accordance with variousaspects of the present disclosure.

FIG. 8 is a diagram illustrating an example process performed, forexample, by a user equipment, in accordance with various aspects of thepresent disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein one skilled in the art should appreciate that the scopeof the disclosure is intended to cover any aspect of the disclosuredisclosed herein, whether implemented independently of or combined withany other aspect of the disclosure. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented withreference to various apparatuses and techniques. These apparatuses andtechniques will be described in the following detailed description andillustrated in the accompanying drawings by various blocks, modules,components, circuits, steps, processes, algorithms, etc. (collectivelyreferred to as “elements”). These elements may be implemented usinghardware, software, or combinations thereof. Whether such elements areimplemented as hardware or software depends upon the particularapplication and design constraints imposed on the overall system.

It is noted that while aspects may be described herein using terminologycommonly associated with 3G and/or 4G wireless technologies, aspects ofthe present disclosure can be applied in other generation-basedcommunication systems, such as 5G and later, including NR technologies.

FIG. 1 is a diagram illustrating a network 100 in which aspects of thepresent disclosure may be practiced. The network 100 may be an LTEnetwork or some other wireless network, such as a 5G or NR network.Wireless network 100 may include a number of BSs 110 (shown as BS 110 a,BS 110 b, BS 110 c, and BS 110 d) and other network entities. A BS is anentity that communicates with user equipment (UEs) and may also bereferred to as a base station, a NR BS, a Node B, a gNB, a 5G node B(NB), an access point, a transmit receive point (TRP), and/or the like.Each BS may provide communication coverage for a particular geographicarea. In 3GPP, the term “cell” can refer to a coverage area of a BSand/or a BS subsystem serving this coverage area, depending on thecontext in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). A BS for a macro cell may bereferred to as a macro BS. A BS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1 , a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some examples, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some examples, the BSs may be interconnected to oneanother and/or to one or more other BSs or network nodes (not shown) inthe access network 100 through various types of backhaul interfaces suchas a direct physical connection, a virtual network, and/or the likeusing any suitable transport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1 , a relay station 110 d may communicate with macro BS 110 a and aUE 120 d in order to facilitate communication between BS 110 a and UE120 d. A relay station may also be referred to as a relay BS, a relaybase station, a relay, etc.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc.These different types of B Ss may have different transmit power levels,different coverage areas, and different impact on interference inwireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 Watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, etc. A UE may be a cellular phone (e.g., asmart phone), a personal digital assistant (PDA), a wireless modem, awireless communication device, a handheld device, a laptop computer, acordless phone, a wireless local loop (WLL) station, a tablet, a camera,a gaming device, a netbook, a smartbook, an ultrabook, medical device orequipment, biometric sensors/devices, wearable devices (smart watches,smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g.,smart ring, smart bracelet)), an entertainment device (e.g., a music orvideo device, or a satellite radio), a vehicular component or sensor,smart meters/sensors, industrial manufacturing equipment, a globalpositioning system device, or any other suitable device that isconfigured to communicate via a wireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolvedor enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEsinclude, for example, robots, drones, remote devices, such as sensors,meters, monitors, location tags, etc., that may communicate with a basestation, another device (e.g., remote device), or some other entity. Awireless node may provide, for example, connectivity for or to a network(e.g., a wide area network such as Internet or a cellular network) via awired or wireless communication link. Some UEs may be consideredInternet-of-Things (IoT) devices, and/or may be implemented as may beimplemented as NB-IoT (narrowband internet of things) devices. Some UEsmay be considered a Customer Premises Equipment (CPE). UE 120 may beincluded inside a housing that houses components of UE 120, such asprocessor components, memory components, and/or the like.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular radioaccess technology (RAT) and may operate on one or more frequencies. ARAT may also be referred to as a radio technology, an air interface,etc. A frequency may also be referred to as a carrier, a frequencychannel, etc. Each frequency may support a single RAT in a givengeographic area in order to avoid interference between wireless networksof different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station) allocates resources forcommunication among some or all devices and equipment within thescheduling entity's service area or cell. Within the present disclosure,as discussed further below, the scheduling entity may be responsible forscheduling, assigning, reconfiguring, and releasing resources for one ormore subordinate entities. That is, for scheduled communication,subordinate entities utilize resources allocated by the schedulingentity.

Base stations are not the only entities that may function as ascheduling entity. That is, in some examples, a UE may function as ascheduling entity, scheduling resources for one or more subordinateentities (e.g., one or more other UEs). In this example, the UE isfunctioning as a scheduling entity, and other UEs utilize resourcesscheduled by the UE for wireless communication. A UE may function as ascheduling entity in a peer-to-peer (P2P) network, and/or in a meshnetwork. In a mesh network example, UEs may optionally communicatedirectly with one another in addition to communicating with thescheduling entity.

Thus, in a wireless communication network with a scheduled access totime-frequency resources and having a cellular configuration, a P2Pconfiguration, and a mesh configuration, a scheduling entity and one ormore subordinate entities may communicate utilizing the scheduledresources.

As indicated above, FIG. 1 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 1 .

FIG. 2 shows a block diagram of a design of BS 110 and UE 120, which maybe one of the base stations and one of the UEs in FIG. 1 . BS 110 may beequipped with T antennas 234 a through 234 t, and UE 120 may be equippedwith R antennas 252 a through 252 r, where in general T>1 and R>1.

At BS 110, a transmit processor 220 may receive data from a data source212 for one or more UEs, select one or more modulation and codingschemes (MCS) for each UE based at least in part on channel qualityindicators (CQIs) received from the UE, process (e.g., encode andmodulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI), etc.) and control information(e.g., CQI requests, grants, upper layer signaling, etc.) and provideoverhead symbols and control symbols. Transmit processor 220 may alsogenerate reference symbols for reference signals (e.g., thecell-specific reference signal (CRS)) and synchronization signals (e.g.,the primary synchronization signal (PSS) and secondary synchronizationsignal (SSS)). A transmit (TX) multiple-input multiple-output (MIMO)processor 230 may perform spatial processing (e.g., precoding) on thedata symbols, the control symbols, the overhead symbols, and/or thereference symbols, if applicable, and may provide T output symbolstreams to T modulators (MODs) 232 a through 232 t. Each modulator 232may process a respective output symbol stream (e.g., for OFDM, etc.) toobtain an output sample stream. Each modulator 232 may further process(e.g., convert to analog, amplify, filter, and upconvert) the outputsample stream to obtain a downlink signal. T downlink signals frommodulators 232 a through 232 t may be transmitted via T antennas 234 athrough 234 t, respectively. According to certain aspects described inmore detail below, the synchronization signals can be generated withlocation encoding to convey additional information.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom BS 110 and/or other base stations and may provide received signalsto demodulators (DEMODs) 254 a through 254 r, respectively. Eachdemodulator 254 may condition (e.g., filter, amplify, downconvert, anddigitize) a received signal to obtain input samples. Each demodulator254 may further process the input samples (e.g., for OFDM, etc.) toobtain received symbols. A MIMO detector 256 may obtain received symbolsfrom all R demodulators 254 a through 254 r, perform MIMO detection onthe received symbols if applicable, and provide detected symbols. Areceive processor 258 may process (e.g., demodulate and decode) thedetected symbols, provide decoded data for UE 120 to a data sink 260,and provide decoded control information and system information to acontroller/processor 280. A channel processor may determine referencesignal received power (RSRP), received signal strength indicator (RSSI),reference signal received quality (RSRQ), channel quality indicator(CQI), etc.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports comprising RSRP, RSSI, RSRQ, CQI, etc.) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to BS 110. At BS 110,the uplink signals from UE 120 and other UEs may be received by antennas234, processed by demodulators 232, detected by a MIMO detector 236 ifapplicable, and further processed by a receive processor 238 to obtaindecoded data and control information sent by UE 120. Receive processor238 may provide the decoded data to a data sink 239 and the decodedcontrol information to controller/processor 240. BS 110 may includecommunication unit 244 and communicate to network controller 130 viacommunication unit 244. Network controller 130 may include communicationunit 294, controller/processor 290, and memory 292.

In some aspects, one or more components of UE 120 may be included in ahousing. Controllers/processors 240 and 280 and/or any othercomponent(s) in FIG. 2 may direct the operation at BS 110 and UE 120,respectively, to perform configuration of a variable timing adjustgranularity. For example, controller/processor 280 and/or otherprocessors and modules at UE 120 may perform or direct operations of UE120 to perform configuration of a variable timing adjust granularity.For example, controller/processor 280 and/or othercontrollers/processors and modules at UE 120 may perform or directoperations of, for example, process 800 of FIG. 8 and/or other processesas described herein. In some aspects, one or more of the componentsshown in FIG. 2 may be employed to perform example process 800 and/orother processes for the techniques described herein. Memories 242 and282 may store data and program codes for BS 110 and UE 120,respectively. A scheduler 246 may schedule UEs for data transmission onthe downlink and/or uplink.

In some aspects, UE 120 may include means for determining at least oneof a granularity or range of a timing adjustment value, means forperforming timing adjustment based at least in part on at least one ofthe granularity or the range of the timing adjustment value, means fordetermining a delay for execution of the timing adjustment based atleast in part on at least one of a numerology associated with UE 120, acarrier associated with UE 120, a band associated with UE 120, or acapability of UE 120, and/or the like. In some aspects, such means mayinclude one or more components of UE 120 described in connection withFIG. 2 .

As indicated above, FIG. 2 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 2 .

FIG. 3 shows an example frame structure 300 for frequency divisionduplexing (FDD) in a telecommunications system (e.g., LTE). Thetransmission timeline for each of the downlink and uplink may bepartitioned into units of radio frames. Each radio frame may have apredetermined duration (e.g., 10 milliseconds (ms)) and may bepartitioned into 10 subframes with indices of 0 through 9. Each subframemay include two slots. Each radio frame may thus include 20 slots withindices of 0 through 19. Each slot may include L symbol periods, e.g.,seven symbol periods for a normal cyclic prefix (as shown in FIG. 3 ) orsix symbol periods for an extended cyclic prefix. The 2L symbol periodsin each subframe may be assigned indices of 0 through 2L−1.

While some techniques are described herein in connection with frames,subframes, slots, and/or the like, these techniques may equally apply toother types of wireless communication structures, which may be referredto using terms other than “frame,” “subframe,” “slot,” and/or the likein 5G NR. In some aspects, a wireless communication structure may referto a periodic time-bounded communication unit defined by a wirelesscommunication standard and/or protocol.

In certain telecommunications (e.g., LTE), a BS may transmit a primarysynchronization signal (PSS) and a secondary synchronization signal(SSS) on the downlink in the center of the system bandwidth for eachcell supported by the BS. The PSS and SSS may be transmitted in symbolperiods 6 and 5, respectively, in subframes 0 and 5 of each radio framewith the normal cyclic prefix, as shown in FIG. 3 . The PSS and SSS maybe used by UEs for cell search and acquisition. The BS may transmit acell-specific reference signal (CRS) across the system bandwidth foreach cell supported by the BS. The CRS may be transmitted in certainsymbol periods of each subframe and may be used by the UEs to performchannel estimation, channel quality measurement, and/or other functions.The BS may also transmit a physical broadcast channel (PBCH) in symbolperiods 0 to 3 in slot 1 of certain radio frames. The PBCH may carrysome system information. The BS may transmit other system informationsuch as system information blocks (SIBs) on a physical downlink sharedchannel (PDSCH) in certain subframes. The BS may transmit controlinformation/data on a physical downlink control channel (PDCCH) in thefirst B symbol periods of a subframe, where B may be configurable foreach subframe. The BS may transmit traffic data and/or other data on thePDSCH in the remaining symbol periods of each subframe.

In other systems (e.g., such NR or 5G systems), a Node B may transmitthese or other signals in these locations or in different locations ofthe subframe.

As indicated above, FIG. 3 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 3 .

FIG. 4 shows two example subframe formats 410 and 420 with the normalcyclic prefix. The available time frequency resources may be partitionedinto resource blocks. Each resource block may cover 12 subcarriers inone slot and may include a number of resource elements. Each resourceelement may cover one subcarrier in one symbol period and may be used tosend one modulation symbol, which may be a real or complex value.

Subframe format 410 may be used for two antennas. A CRS may betransmitted from antennas 0 and 1 in symbol periods 0, 4, 7, and 11. Areference signal is a signal that is known a priori by a transmitter anda receiver and may also be referred to as a pilot signal. A CRS is areference signal that is specific for a cell, e.g., generated based atleast in part on a cell identity (ID). In FIG. 4 , for a given resourceelement with label Ra, a modulation symbol may be transmitted on thatresource element from antenna a, and no modulation symbols may betransmitted on that resource element from other antennas. Subframeformat 420 may be used with four antennas. A CRS may be transmitted fromantennas 0 and 1 in symbol periods 0, 4, 7, and 11 and from antennas 2and 3 in symbol periods 1 and 8. For both subframe formats 410 and 420,a CRS may be transmitted on evenly spaced subcarriers, which may bedetermined based at least in part on cell ID. CRSs may be transmitted onthe same or different subcarriers, depending on their cell IDs. For bothsubframe formats 410 and 420, resource elements not used for the CRS maybe used to transmit data (e.g., traffic data, control data, and/or otherdata).

The PSS, SSS, CRS and PBCH in LTE are described in 3GPP TechnicalSpecification (TS) 36.211, entitled “Evolved Universal Terrestrial RadioAccess (E-UTRA); Physical Channels and Modulation,” which is publiclyavailable.

An interlace structure may be used for each of the downlink and uplinkfor FDD in certain telecommunications systems (e.g., LTE). For example,Q interlaces with indices of 0 through Q−1 may be defined, where Q maybe equal to 4, 6, 8, 10, or some other value. Each interlace may includesubframes that are spaced apart by Q frames. In particular, interlace qmay include subframes q, q+Q, q+2Q, etc., where q E {0, . . . , Q−1}.

The wireless network may support hybrid automatic retransmission request(HARQ) for data transmission on the downlink and uplink. For HARQ, atransmitter (e.g., a BS) may send one or more transmissions of a packetuntil the packet is decoded correctly by a receiver (e.g., a UE) or someother termination condition is encountered. For synchronous HARQ, alltransmissions of the packet may be sent in subframes of a singleinterlace. For asynchronous HARQ, each transmission of the packet may besent in any subframe.

A UE may be located within the coverage of multiple BSs. One of theseBSs may be selected to serve the UE. The serving BS may be selectedbased at least in part on various criteria such as received signalstrength, received signal quality, path loss, and/or the like. Receivedsignal quality may be quantified by a signal-to-noise-and-interferenceratio (SINR), or a reference signal received quality (RSRQ), or someother metric. The UE may operate in a dominant interference scenario inwhich the UE may observe high interference from one or more interferingBSs.

While aspects of the examples described herein may be associated withLTE technologies, aspects of the present disclosure may be applicablewith other wireless communication systems, such as NR or 5Gtechnologies.

New radio (NR) may refer to radios configured to operate according to anew air interface (e.g., other than Orthogonal Frequency DivisionalMultiple Access (OFDMA)-based air interfaces) or fixed transport layer(e.g., other than Internet Protocol (IP)). In aspects, NR may utilizeOFDM with a CP (herein referred to as cyclic prefix OFDM or CP-OFDM)and/or SC-FDM on the uplink, may utilize CP-OFDM on the downlink andinclude support for half-duplex operation using time division duplexing(TDD). In aspects, NR may, for example, utilize OFDM with a CP (hereinreferred to as CP-OFDM) and/or discrete Fourier transform spreadorthogonal frequency-division multiplexing (DFT-s-OFDM) on the uplink,may utilize CP-OFDM on the downlink and include support for half-duplexoperation using TDD. NR may include Enhanced Mobile Broadband (eMBB)service targeting wide bandwidth (e.g., 80 megahertz (MHz) and beyond),millimeter wave (mmW) targeting high carrier frequency (e.g., 60gigahertz (GHz)), massive MTC (mMTC) targeting non-backward compatibleMTC techniques, and/or mission critical targeting ultra reliable lowlatency communications (URLLC) service.

A single component carrier bandwidth of 100 MHZ may be supported. NRresource blocks may span 12 sub-carriers with a sub-carrier bandwidth of75 kilohertz (kHz) over a 0.1 ms duration. Each radio frame may include50 subframes with a length of 10 ms. Consequently, each subframe mayhave a length of 0.2 ms. Each subframe may indicate a link direction(e.g., DL or UL) for data transmission and the link direction for eachsubframe may be dynamically switched. Each subframe may includedownlink/uplink (DL/UL) data as well as DL/UL control data.

Beamforming may be supported and beam direction may be dynamicallyconfigured. MIMO transmissions with precoding may also be supported.MIMO configurations in the DL may support up to 8 transmit antennas withmulti-layer DL transmissions up to 8 streams and up to 2 streams per UE.Multi-layer transmissions with up to 2 streams per UE may be supported.Aggregation of multiple cells may be supported with up to 8 servingcells. Alternatively, NR may support a different air interface, otherthan an OFDM-based interface. NR networks may include entities suchcentral units or distributed units.

The radio access network (RAN) may include a central unit (CU) anddistributed units (DUs). A NR BS (e.g., gNB, 5G Node B, Node B, transmitreceive point (TRP), access point (AP)) may correspond to one ormultiple BSs. NR cells can be configured as access cells (ACells) ordata only cells (DCells). For example, the RAN (e.g., a central unit ordistributed unit) can configure the cells. DCells may be cells used forcarrier aggregation or dual connectivity, but not used for initialaccess, cell selection/reselection, or handover. In some cases, DCellsmay not transmit synchronization signals. In some cases, DCells maytransmit synchronization signals. NR BSs may transmit downlink signalsto UEs indicating the cell type. Based at least in part on the cell typeindication, the UE may communicate with the NR BS. For example, the UEmay determine NR BSs to consider for cell selection, access, handover,and/or measurement based at least in part on the indicated cell type.

As indicated above, FIG. 4 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 4 .

A UE may use a timing adjustment (TA) procedure to apply a temporaloffset to communications of the UE in order to overcome propagationdelay and other types of delay, so that the communications of the UE aresynchronized with those of other UEs when the communications arrive at abase station. In some aspects, timing adjustment is referred to astiming advance. The base station may configure TA by providing a TAcommand identifying an offset to be applied to the communications of theUE. This offset may be defined according to a fixed granularity in someRATs (e.g., LTE). For example, the granularity may be based at least inpart on a tone spacing and system bandwidth of the UE, and thus may befixed in a RAT wherein the tone spacing and system bandwidth are fixed.More particularly, and as an example, the granularity in LTE may beequal to 16 times a sample time of the UE, wherein the sample time isequal to 1/(15 kHZ*2048) seconds, wherein the 2048 value is based atleast in part on a Fast Fourier Transform size of a 20 MHz systembandwidth.

However, 5G/NR may not have a fixed tone spacing and/or systembandwidth. Thus, a fixed TA may cause problems for certain UEs. As aparticular example, a high tone-spacing is often associated with lowcyclic-prefix (to avoid excessive cyclic-prefix overhead). In such acase, a fixed granularity (e.g., associated with LTE) may not besufficient to align all UEs within the narrower cyclic-prefix.Additionally, or alternatively, UEs associated with a higher samplingrate may need a coarser granularity to properly account for TA valuesassociated with large distances from a base station.

Some techniques and apparatuses, described herein, provide foradjustment of a TA granularity and/or delay. For example, sometechniques and apparatuses described herein may provide for implicit orexplicit signaling of a TA granularity to a UE, determination of a TAgranularity by a UE, and/or the like. In this way, UEs associated withdifferent sample times, tone spacing, and/or system bandwidth mayachieve an approximately uniform time unit for TA. This may bebeneficial because a TA offset to be applied may be dependent onmobility events and/or cell-radius, which may be consistent across UEsassociated with different sample times, tone spacing, and/or systembandwidth. Thus, performance of TA is improved, thereby improvingperformance and/or capacity of the cellular network.

FIG. 5 is a diagram illustrating an example 500 of configuring avariable timing adjustment granularity for New Radio, in accordance withvarious aspects of the present disclosure. FIG. 5 is an example whereinTA for a UE 120 is configured during an initial access procedure of theUE 120.

As shown in FIG. 5 , and by reference number 510, the UE 120 may providea random access channel (RACH) preamble to a BS 110. As further shown,the RACH preamble may identify a preferred numerology. For example, theUE 120 may provide information indicating a preferred TA granularity, TArange, and/or TA delay (a delay between signaling of the TA command andapplication of the TA) to the BS 110. In some aspects, the informationmay be included in a physical RACH (PRACH) Message 1, and/or the like.In some aspects, for 4-step RACH, the information may be conveyed usinga PRACH resource-space partition. For example, each partition mayindicate one or more preferred numerologies, and the UE 120 may select apreamble in the partition based at least in part on a numerologyassociated with the partition. In some aspects, for 2-step RACH, theinformation may be conveyed in a payload of PRACH Message 1. The BS 110may use the information to select a TA granularity, TA range, and/or TAdelay for the UE 120.

As shown by reference number 520, the UE 120 may receive a random accessresponse (RAR) from the BS 110. As further shown, the RAR may identify aTA granularity for the UE 120. The TA granularity may be defined basedat least in part on a combination of a coefficient (e.g., N) and asample time (e.g., Ts). In some aspects, the BS 110 may provideinformation indicating N, information indicating Ts, informationindicating the product of N and Ts, and/or information indicating both Nand Ts. The UE 120 may perform TA based at least in part on the TAgranularity, as described in more detail below.

In some aspects, the UE 120 may receive or determine informationidentifying a range of values for TA. The range of values may correspondto a maximum possible cell radius. As an example, for LTE, the maximumpossible cell radius may be approximately 100 km without a secondarycell group (SCG) or 20 km with an SCG. For 5G/NR, the maximum possiblecell radius may be lower, especially in mm Wave and/or the like. In someaspects, the UE 120 may reuse an LTE range of values. In such a case,the UE 120 may tend to use a lower end of the range of values. In someaspects, the UE 120 may use a reduced range of values. This may reducean amount of information needed to indicate the TA command. In someaspects, the UE 120 may use a same number of bits as an LTE TA command,and may interpret the TA command differently (e.g., according to a finergranularity). Thus, the TA range may be effectively reduced. In someaspects, the UE 120 may perform a combination of the above approaches.For example, the UE 120 may use a reduced number of bits and a finergranularity for the TA command.

In some aspects, the TA granularity may be preconfigured. For example,the UE 120 may receive a master information block (MIB), systeminformation (e.g., minimum system information, remaining minimum systeminformation (RMSI), etc.), and/or the like indicating the TAgranularity. Additionally, or alternatively, the UE 120 may determinethe TA granularity. For example, the UE 120 may determine the TAgranularity based at least in part on a numerology of a recent uplinktransmission (e.g., the RACH preamble, etc.), and/or the like.

As shown by reference number 530, the UE 120 may determine the TAgranularity based at least in part on the RAR, and may perform TA basedat least in part on the TA granularity. For example, the UE 120 maysubsequently receive a TA command identifying a TA offset, may interpretthe TA command according to the TA granularity, and may apply the TAoffset accordingly. In this way, a variable TA granularity can be usedfor the UE 120.

As indicated above, FIG. 5 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 5 .

FIG. 6 is a diagram illustrating an example 600 of configuring avariable timing adjustment granularity for New Radio, in accordance withvarious aspects of the present disclosure. FIG. 6 is an example of TAgranularity configuration after an initial access procedure has beenperformed.

As shown in FIG. 6 , and by reference number 610, the UE 120 may receivean uplink scheduling message from the BS 110. As further shown, theuplink scheduling message may include a TA command. The TA command mayindicate a TA offset (e.g., TA value X) to be applied to communicationsof the UE 120. For example, the TA command may indicate a particularvalue, and the UE 120 may interpret the particular value based at leastin part on a TA granularity of the UE 120. In some aspects, the TAcommand may be included in a Media Access Control (MAC) control element(CE).

As shown by reference number 620, the UE 120 may determine the TAgranularity for interpreting the TA command. In some aspects, the UE 120may determine the TA granularity based at least in part on a context inwhich the TA command is received. For example, the UE 120 may determinethe TA granularity based at least in part on a numerology of a messagethat carriers the TA command. Additionally, or alternatively, the UE 120may determine the TA granularity based at least in part on a numerologyof an uplink scheduling message for the TA command, such as the messageshown by reference number 610. Additionally, or alternatively, the UE120 may determine the TA granularity based at least in part on anumerology of a recent uplink transmission, such as a most recentphysical uplink shared channel (PUSCH) transmission, a most recentphysical uplink control channel (PUCCH) transmission, a most recentreference signal transmission, a most recent beam failure recoveryrequest (BFRR) message, and/or the like. Additionally, or alternatively,the UE 120 may determine the TA granularity based at least in part onthe TA command being included in a handover message from a target cell,based at least in part on the TA command being received during regularuplink/downlink scheduling, based at least in part on the TA commandbeing received from the serving cell following an instruction to causethe UE 120 to perform a transmission for TA purposes, and/or the like.

In some aspects, the UE 120 may determine the TA granularity based atleast in part on a most recent scheduled transmission, which reduces alikelihood of a misconfiguration of the TA granularity between the UE120 and the BS 110. In some aspects, the UE 120 may determine the TAgranularity based at least in part on a carrier or band associated withthe UE 120, such as based at least in part on a system bandwidth of thecarrier or band, a tone spacing of the carrier or band, and/or the like.

In some aspects, the TA granularity may be configured. For example, theUE 120 may receive configuration information indicating the TAgranularity (e.g., a master information block (MIB), a systeminformation block (SIB), radio resource control (RRC) messaging, aMAC-CE, downlink control information (DCI), a PDCCH, and/or the like).In some aspects, the TA command may indicate the TA granularity. Forexample, the TA command may indicate a value of N, a value of Ts, and/ora value of both N and Ts, as described in more detail above. In someaspects, the UE 120 may determine the TA granularity based at least inpart on a combination of the above (e.g., configuration information,determination by the UE 120, and/or an indication in the TA command).

As further shown, the UE 120 may perform TA based at least in part onthe TA granularity. For example, the UE 120 may receive a TA commandindicating the TA value of X, and may interpret the value of X accordingto the TA granularity. In this way, the UE 120 performs TA based atleast in part on a variable TA granularity, which improves performanceof TA for UEs with variable tone spacing, system bandwidth, and/or thelike.

As indicated above, FIG. 6 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 6 .

FIG. 7 is a diagram illustrating an example of configuring a variabletiming adjustment granularity for New Radio, in accordance with variousaspects of the present disclosure. FIG. 7 is an example relating todetermination of a TA granularity for a carrier aggregation (CA) ordual-connectivity (DC) UE 120.

As shown in FIG. 7 , and by reference number 710, the UE 120 may beassociated with a group of 3 carriers, which may be referred to hereinas a timing adjustment group (TAG). As further shown, the TAG mayinclude a primary cell (PCell) and two secondary cells (SCells). Asshown, each of the three carriers may be associated with a differentnumerology (e.g., tone spacing and/or system bandwidth).

As shown by reference number 720, the UE 120 may receive a TA commandindicating a TA value X. As further shown, the TA command may designatethe PCell for determination of the TA granularity for the TAG. Forexample, in some aspects, the TA command may designate a particularcarrier or cell of the TAG, and the UE 120 may use a numerologyassociated with the particular carrier or cell to determine a TAgranularity. In some aspects, the particular carrier or cell may bedesignated using a MIB, a minimum system information block (MSIB), another system information block (OSIB), RRC messaging, DCI, agroup-common DCI, a MAC-CE, and/or the like.

As shown by reference number 730, the UE 120 may determine the TAgranularity for the TAG based at least in part on a numerology of thePCell, and may perform TA according to the TA granularity. For example,the UE 120 may use a same TA granularity for the entire TAG, whichsimplifies execution of TA. In some aspects, the UE 120 mayautomatically determine the TA granularity based at least in part on aPCell numerology or a PSCell numerology (e.g., when the TAG includes aPCell or a PSCell).

As a particular example, the TA granularity may be based at least inpart on the following equation:

wherein μ is a subcarrier spacing of the UE 120. T_(c) is a constant,wherein T=1/(Δf_(max)·N_(f)) where Δf_(max)=480·10³ Hz and N_(f)=4096.Thus, the TA granularity may be based at least in part on the numerologyof the UE 120, which is related to the subcarrier spacing. The TAcommand for a TAG may indicate the change of uplink timing relative to acurrent uplink timing of the TAG as a multiple of the above equation.

In some aspects, the UE 120 may use different TA granularities fordifferent cells or carriers. For example, the determination ofrespective TA granularities for a TAG may be based at least in part onrespective parameters of the cells or carriers of the TAG, such asnumerology, bandwidth, tone spacing, and/or the like. In some aspects,the UE 120 may use a combination of the above approaches to determine TAgranularity for a TAG. For example, the UE 120 may use a per-carrierinterpretation, but only for TAGs that do not include a PCell or PSCell.When a TAG includes a PCell or PSCell, the UE 120 may determine the TAgranularity for the TAG based at least in part on the PCell or PSCell.

In some aspects, a UE 120 may determine a delay for execution of TA. Forexample, in LTE, a TA command received in subframe B may be executed insubframe B+6. In 5G/NR, a more flexible approach may be used, whereinthe UE 120 determines the delay. For example, the UE 120 may receiveconfiguration information indicating the delay (e.g., MIB, MSIB, OSIB,RRC, MAC-CE, DCI, group-common DCI, PDCCH, etc.). Additionally, oralternatively, the delay may be indicated in the TA command.Additionally, or alternatively, the UE 120 may determine the delay basedat least in part on a numerology of the UE 120, a carrier of the UE 120,a band of the UE 120, a capability of the UE 120, and/or a combinationof the above.

In some aspects, the TA procedure may be associated with an accuracyrequirement or performance requirement, which is sometimes referred toherein as a performance parameter. For example, in LTE, at a TAgranularity of 16*Ts, an accuracy requirement of 4*Ts may apply for a TScommand, and an accuracy requirement of 24*Ts (for sub-1.4 MHz bands) or12*Ts (for 3 MHz and greater bands) may apply. In 5G/NR, a more flexibleapproach may be used. For example, the accuracy requirement may bedefined as a fixed fraction of the TA granularity (e.g., ¼ of the TAgranularity, ⅛ of the TA granularity, and/or the like). Additionally, oralternatively, the accuracy requirement may be defined as a function ofanother parameter, such as numerology, band, carrier, bandwidth, tonespacing, and/or the like. By using a variable accuracy requirement, theUE 120 may improve performance of the TA procedure.

As indicated above, FIG. 7 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 7 .

FIG. 8 is a diagram illustrating an example process 800 performed, forexample, by a user equipment, in accordance with various aspects of thepresent disclosure. Example process 800 is an example where a userequipment (e.g., UE 120) performs configuration of a variable timingadjustment granularity for New Radio.

As shown in FIG. 8 , in some aspects, process 800 may includedetermining at least one of a granularity or range of a timingadjustment value (block 810). For example, the user equipment (e.g.,using controller/processor 280 and/or the like) may determine at leastone of a TA granularity or a range of a TA value. In some aspects, theuser equipment may perform the determination based at least in part onat least one of a TA command, configuration information, informationregarding a communication, carrier, or band associated with the userequipment, or a combination thereof. In some aspects, the granularity orthe range may be variable based at least in part on the communication,carrier, or band associated with the user equipment.

As shown in FIG. 8 , in some aspects, process 800 may optionally includedetermining a delay for execution of timing adjustment based at least inpart on at least one of a numerology, a carrier, a band, or a capability(block 820). For example, in some aspects, the user equipment (e.g.,using controller/processor 280 and/or the like) may determine a delayfor execution of the timing adjustment. The determination may be basedat least in part on a numerology of the user equipment, a carrier of theuser equipment, a band of the user equipment, or a UE capability of theuser equipment.

As shown in FIG. 8 , in some aspects, process 800 may include performingtiming adjustment based at least in part on at least one of thegranularity or the range of the timing adjustment value (block 830). Forexample, the user equipment (e.g., using controller/processor 280,transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252,and/or the like) may perform TA (e.g., a TA procedure) based at least inpart on at least one of the granularity or the range of the TA value. Insome aspects, the user equipment may interpret the TA value according tothe granularity and/or the range to determine a TA offset, and may applythe TA offset to communications of the user equipment after the delayhas elapsed. In some aspects, the user equipment may perform the timingadjustment based at least in part on a timing adjustment command,configuration information regarding the granularity, informationregarding a communication, carrier, or band associated with the userequipment, or a combination thereof.

Process 800 may include additional aspects, such as any single aspect orany combination of aspects described below and/or in connection with oneor more other processes described elsewhere herein.

In some aspects, the timing adjustment command indicates at least one ofa value of a coefficient for determining the timing adjustment value,the sample time of the user equipment, or a combination of the sampletime and the value of the coefficient.

In some aspects, the configuration information includes at least one ofa master information block, a system information block, radio resourcecontrol (RRC) information, a media access control control element(MAC-CE), downlink control information (DCI), a group-common DCI, or aphysical downlink control channel.

In some aspects, the information regarding the communication, carrier,or band associated with the user equipment includes at least one of anumerology of a downlink shared channel that provides the timingadjustment command, a numerology of a downlink control channel thatschedules the downlink shared channel, a numerology of an uplinktransmission of the user equipment, or a numerology of a scheduleduplink transmission of the user equipment.

In some aspects, the determination is based at least in part on acontext in which the timing adjustment command is received. In someaspects, the determination is based at least in part on whether thetiming adjustment command is received in a handover message. Forexample, in some aspects, the determination is based at least in part onwhether the timing adjustment command is received from a serving cell ofthe user equipment during data scheduling. For example, in some aspects,the determination is based at least in part on whether the timingadjustment command is received from a serving cell in association withan instruction to cause the user equipment to perform an uplinktransmission for timing adjustment purposes.

In some aspects, the timing adjustment is performed after an initialaccess procedure is performed. In some aspects, the timing adjustment isperformed during an initial access procedure of the user equipment. Insome aspects, the configuration information includes at least one of amaster information block (MIB) or a remaining minimum system information(RMSI). In some aspects, the information regarding the communication,carrier, or band associated with the user equipment relates to a randomaccess message transmitted by the user equipment. In some aspects, therandom access message indicates a preferred numerology of the userequipment. In some aspects, the preferred numerology is indicated usinga random access channel resource-space partition. In some aspects, thepreferred numerology is indicated in a payload sent with an initial RACHmessage.

In some aspects, the timing adjustment is performed for a timingadjustment group (TAG) that share the timing adjustment command. In someaspects, the TAG includes a primary cell (PCell) or a primary secondarycell (PSCell), and a numerology of the PCell or the PSCell is used todetermine the granularity of the timing adjustment value of the TAG. Insome aspects, a particular cell of the TAG is designated, using theconfiguration information, for determination of the granularity of thetiming adjustment value of the TAG. In some aspects, the timingadjustment command is interpreted differently for a first cell of theTAG than for a second cell of the TAG based at least in part onrespective numerologies of the first cell and the second cell.

In some aspects, the configuration information further indicates a delayfor execution of the timing adjustment. In some aspects, the timingadjustment command indicates a delay for execution of the timingadjustment. In some aspects, the user equipment may determine a delayfor execution of the timing adjustment based at least in part on atleast one of a numerology associated with the user equipment, a carrierassociated with the user equipment, a band associated with the userequipment, or a capability of the user equipment.

In some aspects, a performance parameter (e.g., an accuracy requirement,a performance requirement, etc.) for the timing adjustment is based atleast in part on a particular fraction of the granularity of the timingadjustment. In some aspects, a performance parameter for the timingadjustment is based at least in part on at least one of the granularityof the timing adjustment, a numerology associated with the userequipment, a carrier associated with the user equipment, a bandassociated with the user equipment, or a capability of the userequipment.

Although FIG. 8 shows example blocks of process 800, in some aspects,process 800 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 8 .Additionally, or alternatively, two or more of the blocks of process 800may be performed in parallel.

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the aspects to the preciseform disclosed. Modifications and variations are possible in light ofthe above disclosure or may be acquired from practice of the aspects.

As used herein, the term component is intended to be broadly construedas hardware, firmware, or a combination of hardware and software. Asused herein, a processor is implemented in hardware, firmware, or acombination of hardware and software.

Some aspects are described herein in connection with thresholds. As usedherein, satisfying a threshold may refer to a value being greater thanthe threshold, greater than or equal to the threshold, less than thethreshold, less than or equal to the threshold, equal to the threshold,not equal to the threshold, and/or the like.

It will be apparent that systems and/or methods, described herein, maybe implemented in different forms of hardware, firmware, or acombination of hardware and software. The actual specialized controlhardware or software code used to implement these systems and/or methodsis not limiting of the aspects. Thus, the operation and behavior of thesystems and/or methods were described herein without reference tospecific software code—it being understood that software and hardwarecan be designed to implement the systems and/or methods based, at leastin part, on the description herein.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of possible aspects. In fact, many ofthese features may be combined in ways not specifically recited in theclaims and/or disclosed in the specification. Although each dependentclaim listed below may directly depend on only one claim, the disclosureof possible aspects includes each dependent claim in combination withevery other claim in the claim set. A phrase referring to “at least oneof” a list of items refers to any combination of those items, includingsingle members. As an example, “at least one of: a, b, or c” is intendedto cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combinationwith multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c,a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering ofa, b, and c).

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems, and may be used interchangeably with “one or more.” Furthermore,as used herein, the terms “set” and “group” are intended to include oneor more items (e.g., related items, unrelated items, a combination ofrelated and unrelated items, etc.), and may be used interchangeably with“one or more.” Where only one item is intended, the term “one” orsimilar language is used. Also, as used herein, the terms “has,” “have,”“having,” and/or the like are intended to be open-ended terms. Further,the phrase “based on” is intended to mean “based, at least in part, on”unless explicitly stated otherwise.

What is claimed is:
 1. A method of wireless communication performed by auser equipment (UE), comprising: receiving a timing adjustment commandthat indicates a value for timing adjustment; and performing a timingadjustment based at least in part on a timing adjustment offset, whereinthe timing adjustment offset is based at least in part on the value fortiming adjustment and a granularity, and wherein the granularity isbased at least in part on a numerology associated with the UE.
 2. Themethod of claim 1, wherein the numerology, on which the granularity isbased, is a numerology of an uplink transmission of the UE.
 3. Themethod of claim 1, wherein the timing adjustment is performed for atiming adjustment group (TAG) that shares the timing adjustment command.4. The method of claim 3, wherein the numerology, on which thegranularity is based, is a numerology associated with a designatedcarrier of the TAG.
 5. The method of claim 1, wherein the timingadjustment is performed after an initial access procedure is performed.6. The method of claim 1, wherein the timing adjustment is performedbased at least in part on receiving a random access response (RAR). 7.The method of claim 1, wherein the timing adjustment is performed aftera delay that is based at least in part on the numerology, wherein thedelay is between signaling of the timing adjustment command andapplication of the timing adjustment.
 8. The method of claim 1, whereinthe timing adjustment is performed after a delay that is based at leastin part on a capability of the UE, wherein the delay is betweensignaling of the timing adjustment command and application of the timingadjustment.
 9. A user equipment (UE) for wireless communication,comprising: a memory; and one or more processors coupled to the memoryand configured to: receive a timing adjustment command that indicates avalue for timing adjustment; and perform a timing adjustment based atleast in part on a timing adjustment offset, wherein the timingadjustment offset is based at least in part on the value for timingadjustment and a granularity, and wherein the granularity is based atleast in part on a numerology associated with the UE.
 10. The UE ofclaim 9, wherein the numerology, on which the granularity is based, is anumerology of an uplink transmission of the UE.
 11. The UE of claim 9,wherein the timing adjustment is performed for a timing adjustment group(TAG) that shares the timing adjustment command.
 12. The UE of claim 11,wherein the numerology, on which the granularity is based, is anumerology associated with a designated carrier of the TAG.
 13. The UEof claim 9, wherein the timing adjustment is performed after an initialaccess procedure is performed.
 14. The UE of claim 9, wherein the timingadjustment is performed based at least in part on receiving a randomaccess response (RAR).
 15. The UE of claim 9, wherein the timingadjustment is performed after a delay that is based at least in part onthe numerology, wherein the delay is between signaling of the timingadjustment command and application of the timing adjustment.
 16. The UEof claim 9, wherein the timing adjustment is performed after a delaythat is based at least in part on a capability of the UE, wherein thedelay is between signaling of the timing adjustment command andapplication of the timing adjustment.
 17. A non-transitorycomputer-readable medium storing one or more instructions for wirelesscommunication, the one or more instructions comprising: one or moreinstructions that, when executed by one or more processors of a userequipment (UE), cause the one or more processors to: receive a timingadjustment command that indicates a value for timing adjustment; andperform a timing adjustment based at least in part on a timingadjustment offset, wherein the timing adjustment offset is based atleast in part on the value for timing adjustment and a granularity, andwherein the granularity is based at least in part on a numerologyassociated with the UE.
 18. The non-transitory computer-readable mediumof claim 17, wherein the numerology, on which the granularity is based,is a numerology of an uplink transmission of the UE.
 19. Thenon-transitory computer-readable medium of claim 17, wherein the timingadjustment is performed for a timing adjustment group (TAG) that sharesthe timing adjustment command.
 20. The non-transitory computer-readablemedium of claim 17, wherein the timing adjustment is performed after aninitial access procedure is performed.
 21. The non-transitorycomputer-readable medium of claim 17, wherein the timing adjustment isperformed based at least in part on receiving a random access response(RAR).
 22. The non-transitory computer-readable medium of claim 17,wherein the timing adjustment is performed after a delay that is basedat least in part on the numerology, wherein the delay is betweensignaling of the timing adjustment command and application of the timingadjustment.
 23. The non-transitory computer-readable medium of claim 17,wherein the timing adjustment is performed after a delay that is basedat least in part on a capability of the UE, wherein the delay is betweensignaling of the timing adjustment command and application of the timingadjustment.
 24. An apparatus for wireless communication, comprising:means for receiving a timing adjustment command that indicates a valuefor timing adjustment; and means for performing a timing adjustmentbased at least in part on a timing adjustment offset, wherein the timingadjustment offset is based at least in part on the value for timingadjustment and a granularity, and wherein the granularity is based atleast in part on a numerology associated with the apparatus.
 25. Theapparatus of claim 24, wherein the numerology, on which the granularityis based, is a numerology of an uplink transmission of the apparatus.26. The apparatus of claim 24, wherein the timing adjustment isperformed for a timing adjustment group (TAG) that shares the timingadjustment command.
 27. The apparatus of claim 24, wherein the timingadjustment is performed after an initial access procedure is performed.28. The apparatus of claim 24, wherein the timing adjustment isperformed based at least in part on receiving a random access response(RAR).
 29. The apparatus of claim 24, wherein the timing adjustment isperformed after a delay that is based at least in part on thenumerology, wherein the delay is between signaling of the timingadjustment command and application of the timing adjustment.
 30. Theapparatus of claim 24, wherein the timing adjustment is performed aftera delay that is based at least in part on a capability of the apparatus,wherein the delay is between signaling of the timing adjustment commandand application of the timing adjustment.
 31. A method of wirelesscommunication performed by a user equipment (UE), the method comprising:determining a respective granularity of a timing adjustment value foreach of a plurality of carriers based at least in part on a timingadjustment command indicating the timing adjustment value for a timingadjustment group (TAG) of the carriers that share the timing adjustmentcommand, wherein the respective granularity is variable based at leastin part on a numerology associated with a cell of the TAG; andperforming timing adjustment based at least in part on the respectivegranularity of the timing adjustment value, wherein the timingadjustment command is interpreted differently for a first cell of theTAG than for a second cell of the TAG based at least in part onrespective numerologies of the first cell and the second cell.
 32. Auser equipment (UE) for wireless communication, comprising: a memory;and one or more processors coupled to the memory and configured to:determine a respective granularity of a timing adjustment value for eachof a plurality of carriers based at least in part on a timing adjustmentcommand indicating the timing adjustment value for a timing adjustmentgroup (TAG) of the carriers that share the timing adjustment command,wherein the respective granularity is variable based at least in part ona numerology associated with a cell of the TAG; and perform timingadjustment based at least in part on the respective granularity of thetiming adjustment value, wherein the timing adjustment command isinterpreted differently for a first cell of the TAG than for a secondcell of the TAG based at least in part on respective numerologies of thefirst cell and the second cell.